Complete the equation of the line through $(3,-1)$ and $(4,7)$. Use exact numbers. $y=$
Explanation: Let's find the slope: $\begin{aligned} \text{Slope}&=\dfrac{7-(-1)}{4-3} \\\\ &=\dfrac{8}{1} \\\\ &=8 \end{aligned}$ The equation is $y=8x+b$ for some $b$. Let's plug the point $({4},{7})$ to find $b$ : $\begin{aligned} y&=8 x+b \\\\ {7}&=8({4})+b \\\\ 7&=32+b \\\\ -25&=b \end{aligned}$ The equation is $y=8x -25$.